by wurzel » Wed Aug 22, 2018 10:12 am
I had a similar problem with my 2011 2.4 AWD 350 in as much as they would not self park with intermittent or continuous or with the single screen mist wipe.
It turned out to be worn contacts in the motor.
I replaced the whole wiper motor with an aftermarket one as the Ford one was pricey and its been fine for two years and resolved all the problems
I'm not sure if your issue is the same, could be the early stages of the contacts wearing
Out of curiosity I looked at the old unit, simply removed the cover plate and I reckon I could have cleaned and adjusted the brass contacts to give it a bit more life, you could clearly see the wear and poor contact they were suffering from.
Its not difficult to remove the wiper motor so might be worth having a peek first
Good luck